It is widely believed that yo-yos originated in China, although the earliest recorded documentary evidence of the toy comes from Greece, circa 500 BC. The yo-yo has long been extremely popular among children of the Philippines. A picture of a girl in a red dress playing with her yo-yo appears on a box from India made in the year 1765. During the late 18th century, the yo-yo gained popularity among the aristocracy of Scotland, France and England.
The usefulness of the yo-yo as a stress reliever is widely known. In fact, it is reported that unfortunate people played with their "emigrettes" (French term for yo-yo) to reduce tension on their way to the guillotine.
Yo-yos were probably introduced to the United States in the 19th century. There are several patents related to yo-yos in the 1860's, referring to them as "bandalores" and "return wheels". Perhaps one of the earliest references to the term "yo-yo" in the United States was a Jul. 1, 1916 Scientific American Supplement describing various Filipino toys and explaining that "yo-yo" was derived from the Filipino word for "come-come". This origin was later corroborated by Dr. Henry Lee Smith, Jr. in the famous Duncan yo-yo trademark case of 1965. Dr. Smith, who was then Chairman of the Department of Anthropology and Linguistics and Professor of Linguistic English, State University of New York at Buffalo, testified in the case as an expert liguist and etymologist that it was his opinion that the word "yo-yo" is a Malayo-Polynesian word of Philippine origin, and that the toy itself was of Oriental origin.
The first large-scale commercial yo-yo production in the United States can be traced to Pedro Flores of the Philippines, who brought the first Filipino yo-yo to the United States and opened a yo-yo manufacturing company under his own name in 1928. Flores' yo-yos were made of wood and included a string looped about the axle, permitting the yo-yo to "sleep" and do other tricks.
The Flores yo-yo company was purchased by Donald F. Duncan Sr. in the late 1920s. The Duncan Company prospered for many years as a leading producer of yo-yos, producing tens of millions of yo-yos each year. During the time period of 1932-1965, Duncan actually owned a federal trademark registration for the term "yo-yo". The term was judged to be generic, and therefore incapable of trademark significance in Donald F. Duncan, Inc. v. Royal Tops Manufacturing Company, Inc., 144 USPQ 617 (7th Cir. 1965). Later in the same year, the Duncan Company filed for bankruptcy.
The yo-yo has been known by many names over the years including: L'emigrette (French for "leave the country"), de Coblenz (name of a French city to which many French fled), joujou de Normandie, bandalore, quiz, incroyable, Prince of Wales, return wheel, return top, come-back, return, whirl-a-gig and twirler. One patent even refers to a specially designed yo-yo as, "A toy having combined rotational motion about a horizontal axis and translational motion in a vertical direction." (U.S. Pat. No. 4,290,224, Sept. 22, 1981, Abstract).
Despite the numerous names by which the toy has been known, and the numerous yo-yo manufacturers making yo-yos over the years, basic yo-yo design has changed very little over the years. Originally, all yo-yos made in the United States were made of wood. The original shape was known as the "Imperial". The Imperial, or standard shape yo-yo, is especially suitable for loop tricks.
The Duncan Company later introduced the Butterfly design. The design of the Butterfly reverses the halves of a traditional Imperial design yo-yo. The Butterfly design is especially attractive to young players because it is very easy to catch, although somewhat uncomfortable to hold. Duncan and others also pioneered the switch from wood to plastic in yo-yo manufacture.
Most design changes in yo-yos have come about in an effort to improve the ability of the yo-yo to perform certain tricks. There are hundreds of known yo-yo tricks. Among the better known are the Sleeper (AKA The Spinner), the Forward Pass, the Breakaway, the Creeper, Rock the Baby, the Buzsaw, the One Handed Star and the Bank Deposit. While the Duncan Company pioneered the use of touring professionals who demonstrated yo-yo tricks, there are presently yo-yo competitions and shows on regional, state, national and international levels.
There are three basic yo-yo characteristics that enable most tricks. First, the yo-yo must be capable of sleeping for an extended period of time. A yo-yo is said to "sleep" when it has been released from the user's hand, and begins to rapidly spin about its axis at the end of the tether without return. At the end of a sleeping trick the user then tugs or jerks on the tether to cause the yo-yo to return. A second desired characteristic is that of avoiding inadvertent snagging or grabbing of the tether, causing premature return. A third and final desired characteristic is the ability of the yo-yo to return on command. Various manufacturers have offered design improvements to address one or more of these desired characteristics. Recently, manufacturers have attempted to design yo-yos having characteristics that can be changed on demand or between or even during tricks.
The dynamics of "sleeping" are explained in U.S. Pat. No. 5,100,361 (Kuhn and Watson)(1992). In this patent, directed to the commercially available SB-2.TM. adjustable yo-yo (available from What's Next Manufacturing Co., Inc. of Arcade, New York), it is explained that:
A Yo-Yo "sleeping" must be "waked"; that is caused to engage the string at the axle, initiating rewinding of the string in the space between the sides and, with momentum, return the Yo-Yo to the players hand "in " the Yo-Yo: a toy Fly Wheel, AMERICAN SCIENTIST, Vol. 72, March-April 1984, pp. 137-142, Wolfgang Burger explains that the sleeping Yo-Yo is waked by a sudden pull on the string. Consequent interactions between the string and the rotating parts of the Yo-Yo caused the string to be wrapped tightly around the axle, and in the space between the Yo-Yo sides, returning the Yo-Yo to the players hand. Burger mentions, "capstan friction", which occurs between the portion of string looped around the axle and the peripheral surface of the rotating axle, as an initiating cause for the rewinding of the string. Capstan friction acts to slow the spinning of the yo-yo resulting in undesirable, early termination of play in sleeping tricks; capstan friction also acts to fray the string at the axle resulting in short play life of the string and possible damage of the Yo-Yo if the string breaks during play. (U.S. Pat. No. 5,100,361, col. 1, lines 29-53; note that although the word "yo-yo" is capitalized in the text, What's Next Manufacturing Co, Inc., also assignee of the present patent, considers the phrase "yo-yo" to be a generic term, incapable of trademark significance.)
Attempts have been made to reduce and eliminate the aforementioned capstan friction in order to extend significantly the spin time in a single throw of the yo-yo.
During the 1970s, yo-yo manufacturers modified designs to distribute weight about the rim. For example, U.S. Pat. No. 3,805,443 (Donald Duncan Jr.) discloses a yo-yo with maximum weight distributed in the outer periphery and also has a uniquely shaped side member that enables the yo-yo to sleep for an extended period of time. This design change resulted in a longer sleep time.
U.S. Pat. No. 4,130,962 Ennis 1978 describes a smooth axle of reduced diameter providing lower friction, meaning in fact, lower retarding torque. It also disposes the weight of the yo-yo in the periphery of the disks. This provides the yo-yo with a flywheel effect by placing the weight of the yo-yo nearest periphery. Ennis also describes cone-shaped protuberances with rounded ends situated circularly on the inside spaces of the disks proximate the central axle where the rounded tip protuberance snare loose ends of the wind up string for wind up.
U.S. Pat. No. 4,895,547 (Amaral)(1990) describes the elimination of capstan friction between the string and axle by placing a low friction sleeve bearing on the central axle and looping the string around the sleeve. The invention also includes an arrangement of radially extending raised ribs extending from the inwardly facing surfaces of the yo-yo halves and arranged to engage the string when retrieving the yo-yo
U.S. Pat. No. 3,175,326 (Isaacson)(1965) eliminates capstan friction by using a ball bearing on the central axle with a specialized ring mounted at the periphery of the bearing and with the string looped around the ring.
Each of the three patents cited above (Ennis, Amaral and Isaacson) describes yo-yo embodiments where no provision is made to adjust the width of the gap between the yo-yo sides. The aforementioned U.S. Pat. No. 5,100,361 (Tom Kuhn and Donald W. Watson)(1992)(SB-2) discloses a yo-yo having a frictionless axle bearing for extended spin time. This invention also offers infinitely fine adjustment of the gap between the sides of the yo-yo for thread engagement. The adjustment is done by separating the yo-yo halves, and adjusting the gap by means of a tool or fingernail. This enables the yo-yo gap to be preset to accomplish certain types of tricks. While this yo-yo is a major improvement over the prior art, it suffered from the requirement of disassembling the yo-yo to make the gap adjustment.
Other attempts to adjust the engagement tension on the tether include U.S. Pat. Nos. 5,813,897 and 5,813,898 (Van Dan Elzen et al.) which relate to yo-yos having a plurality of recessed grooves in the tether facing surface of each of the yo-yos side pieces. Embedded in the grooves are rubber pads that tend to grab the string, facilitating a more reliable return of the yo-yo. Both of these patents disclose a starburst pattern of the rubber pads. While these inventions offer definite improvements in string control, unfortunately the design of these yo-yos requires expensive machining of the yo-yo halves as well as intricate placement of the pads within the grooves. Moreover, the rubber pads tend to fray the string causing premature wear. Also, these inventions do not afford adjustment of the tether gap.
In addition to the major yo-yo developments discussed above, others have made significant contributions to the yo-yo art in a variety of areas.
In 1975, Gil C. Sanchez patented (U.S. Pat. No. 3,924,114) an illuminated yo-yo.
In 1980, Tom Kuhn patented (U.S. Pat. No. 4,207,701) the "No Jive 3-in-1" yo-yo, the first yo-yo which could be taken apart by hand and reassembled in either the Imperial or Butterfly configuration. This patented yo-yo was also the first to have a replaceable axle.
In 1980, Michael Caffrey patented (U.S. Pat. No. 4,332,102) "The yo-yo with a Brain", a yo-yo having a free-spinning sleeve bearing and centrifugal spring loaded clutch that cause an automatic return when the rotational speed slows to a predetermined rate.
In 1984, Patrick MacCarthy patented (U.S. Pat. No. 4,437,261) a yo-yo having a twist resistant string offering a greater torsional resistance to twisting about the axis of the string than other conventional strings.
In 1991, Thomas F. Haley patented (U.S. Pat. No. 5,035,667) a swivel device for preventing twisting of a yo-yo string.
In 1995, John J. McAvoy, Jr. patented (U.S. Pat. No. 5,254,027) an adjustable performance yo-yo capable of adjusting the frictional drag applied to the yo-yo string This invention is designed to maximize sleep time while simultaneously enabling return of the yo-yo to the hand at will.
In 1998, Donald F. Duncan et al. patented (U.S. Pat. No. 5,769,686) a yo-yo having a unique axle design and end pieces capable of retaining Pog-shaped inserts.
Despite the numerous advances in yo-yo design over the years, heretofore a yo-yo has not been invented that offers long sleep time, prompt and reliable return upon request by the user's hand, and adjustable gap adjustment without disassembly. There has clearly been a longfelt need for a yo-yo with these characteristics.